1. Expression Blend 4 – deep dive
Christian Moser
User Experience Architect
Zühlke Engineering AG

2. Microsoft’s vision for XAML (2006)
“…XAML rocks because designers can work in tandem with developers…”
“…A byproduct of XAML's expressivity and comprehensiveness is true separation of user interface and business logic. “
“…using Blend, a designer can access the full expressivity of XAML – layout, graphics, controls, templating and styling, animations, data binding, and basic 3D.” 

3. A new way of collaboration

4. Interactive Designer (2006)

5. Expression Blend (2008)

6. Expression Studio

7. The ideal collaboration
Developer
Designer
Connector to backend & business logic
Provides data and commands to UI
Creates a basic user interface
Improves the interaction by arranging and replacing controls
Creates (or imports) the visual style

8. Real world collaboration problems
The features of Blend (XAML) are too limited. Code is required to build the desired interaction.
The classical way of UI programming (using code behind) is not flexible enough.
The designer knows too less about Silverlight or WPF or software architecture.
What is a control template, dependency property or trigger?
Where to place resources?

9. Sample Project
digitalworld.

10. The developer’s part for a working collaboration: Separation of Logic and Presentation

11. How to separate logic and view
The model must not know about the view
Using DataBinding is the best way to synchronize data between the view and the model
Binding to the DataContext is very convenient, since it’s the default source.
The DataContext is inherited from parent to child
There is only one DataContext
To access multiple objects you need to aggregate them to one «facade».

12. Model-View-ViewModel II
DataContext

13. Advantages of the MVVM pattern
The ViewModel defines a clear data contract for the view
Through Properties, Lists and Commands
Designers can use the contract to create sample data or binding hints
Controls can easily be replaced without touching code
Developers can test against the ViewModel without creating the view (using UnitTests).

14. Demo

15. Designtime vs. Runtime Experience

16. Typical design time issues
At designtime
 Wrong size
 No data
At runtime

17. At design time UserControls are not embedded in a parent view
Width and Height are not set
The root-element constructor is not called
Root Element is replaced by the designer
ViewModel is not created
Controls behave different
No mouse and keyboard events
Design time extensions loaded

18. Design time attributes
xmlns:d =" xmlns:mc=" compatibility/2006" mc:Ignorable="d"
Attribute
Function
d:DesignHeight
Overrides the height at design time
d:DesignWidth
Overrides the width at design time
d:DataContext
Overrides the data context at design time
d:DesignData
Creates sample data from a XAML file
d:DesignInstance
Creates an instance of a type

19. Design width and height
<UserControl xmlns=" xmlns:x= d:DesignWidth="640" d:DesignHeight="480" > <UserControl />
Tipp: Blend and Visual Studio provide special handles to set design time size

20. Generic Sample Data
<Application.Resources> <SampleData:ProductSampleData x:Key="data" d:IsDataSource="True"/> </Application.Resources> <Border d:DataContext="{Binding Source={StaticResource data}}" > <ListBox ItemsSource="{Binding Products}" /> </Border>

21. Sample Data from Type
d:DesignData creates a proxy of the specified type and sets the values
This brings the following advantages
Types without public or default constructor can be created from XAML
Readonly properties can be set
The designer knows about the interface to support data binding.

22. Sample Data from Type
ProductSampleData.xaml: <l:Product xmlns:l="clr-namespace:DigiShop" Name="HP Notebook" Description= "This powerful device provides…" Price="499.90"> <l:Product.Category> <l:Category Name="Notebooks"/> </l:Product.Category> </l:Product> <StackPanel DataContext="{Binding Products.CurrentItem}" d:DataContext="{d:DesignData ProductSampleData.xaml}" > <Image Source="{Binding Picture}" /> <TextBlock Text="{Binding Name}" /> </StackPanel>

23. Demo

24. More Interactivity with less code

25. XAML limitations
Today designers would need to write code to do basic scenarios like:
validation
drag&drop
starting a storyboard
Expression Blend features are limited by the expressiveness of XAML
A developer needs to support the designer to build these interactions

26. Selfmade: Attached Helpers
<TextBox l:TextBoxHelper.UpdateOnEnter="True" />

27. Disatvantages of this solution
No designer support in Expression Blend
You need to start from scratch
Register a DependencyProperty to hook up the helper
Wiring up to events
Handle conditions
Detaching and disposing

28. Actions and Behaviors
System.Windows.Interactivity.dll

29. Hunderts of Behaviors out there
InvokeCommandAction
CallMethodAction
GoToStateAction
PlaySoundAction
PlayMediaAction
RevindMediaAction
TogglePlayPauseMediaAction
HyperlinkAction
SetDataStoreValueAction
ChangePropertyAction
RemoveElementAction
CallDataMethod
InvokeDataCommand
FluidBindPropertyBehavior
DataStateBehavior
ClippingBehavior
GoToNextStateBehavior
ShowMessageBoxBehavior
MouseDragElementBehavior
FluidMoveBehavior
FluidMoveSetTagBehavior
TextBoxEditMaskBehavior
ListBoxAddOne
ListBoxRemoveOne

30. Actions in Action Actions can be attached to any element
<Image Source="{Binding Picture}">
<i:Interaction.Triggers>
<i:EventTrigger EventName="MouseLeftButtonDown"> <i:InvokeCommandAction Command="{Binding AddToCartCommand}"/> </i:EventTrigger>
</i:Interaction.Triggers>
</Image>

31. How to use Behaviors Behaviors can be attached to any element
<Image Source="digitalworld.png" >
<i:Interaction.Behaviors>
<ei:MouseDragElementBehavior/>
</i:Interaction.Behaviors>
</Image>

32. Create your own behavior
public class MyBehavior : Behavior<FrameworkElement> {
protected override void OnAttached()
base.OnAttached();
AssociatedObject.MouseEnter += OnMouseEnter; }
protected override void OnDetaching()
base.OnDetaching();
AssociatedObject.MouseEnter -= OnMouseEnter;
private static void OnMouseEnter(object sender, MouseEventArgs e)
MessageBox.Show("It works!");

33. Demo

34. States and Transitions

35. Button (State Machine)
States of controls
Button (State Machine)

36. States using Triggers in WPF
<Style x:Key="MyButtonStyle" TargetType="{x:Type Button}">
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="White" />
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Background" Value="Gray" />
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Opacity" Value="0.5" />
</Style.Triggers>
</Style>

37. Visual State Manager

38. All Silverlight and WPF4 controls support states
[TemplateVisualState(Name = "ContentFocused", GroupName = "FocusStates")] [TemplateVisualState(Name = "MouseOver", GroupName = "CommonStates")] [TemplateVisualState(Name = "Focused", GroupName = "FocusStates")] [TemplateVisualState(Name = "Checked", GroupName = "CheckStates")] [TemplateVisualState(Name = "Unchecked", GroupName = "CheckStates")] [TemplateVisualState(Name = "Indeterminate", GroupName = "CheckStates")] [TemplateVisualState(Name = "Pressed", GroupName = "CommonStates")] [TemplateVisualState(Name = "Disabled", GroupName = "CommonStates")] [TemplateVisualState(Name = "Unfocused", GroupName = "FocusStates")] [TemplateVisualState(Name = "Normal", GroupName = "CommonStates")] public class CheckBox : ToggleButton {
.... }

39. Easing Functions Make animations feel more natural
<DoubleAnimationUsingKeyFrames … >
<EasingDoubleKeyFrame KeyTime="0:0:3" Value="370">
<EasingDoubleKeyFrame.EasingFunction>
<BounceEase EasingMode="EaseOut"/>
</EasingDoubleKeyFrame.EasingFunction>
</EasingDoubleKeyFrame>
</DoubleAnimationUsingKeyFrames>

40. Reasons for Visual State Manager
VSM can be attached to any control without code
All Silverlight and WPF 4.0 controls support VSM.
State transitions are created automatically
Supports TransitionEffects and Easing
Good support in Expression Blend
Additional States can be added
States can be switched from externally

41. Creating custom easing functions
class CoolEasingFunction : EasingFunctionBase {
protected override double EaseInCore(double normalizedTime)
return Math.Abs(Math.Sin(normalizedTime * Math.PI * 2))
* normalizedTime; }
protected override Freezable CreateInstanceCore()
return new CoolEasingFunction();

42. Demo

43. Summary
The way of programming WPF and Silverlight has become more declarative
This makes design tools more powerful
Designers can do more without the need of writing code
Complexity is hidden within smart reusable extensions like VSM or Behaviors
The collaboration between designers and developers can be improved.

44. Want more information? Meet me at the «Ask the Expert» lounge
Contact Information:
Christian Moser
Zühlke Engineering AG
Wiesenstrasse 10a 8952 Schlieren
Mail: Blog: Twitter: @moser_christian

45. Resources
The new Iteration
Design-Time Attributes:
PathListBoxUtils

46. 4/6/ :35 AM
© 2011 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.